1. Field of the invention
The present invention is related to a backflow proof structure for a syringe, and especially to a backflow proof structure for a syringe which can prevent injection liquid from back flowing and from contacting with air or other pollution sources and can prevent recovery and reusing of the syringe. It can be applied for huge or small types of medical treatment establishments.
2. Description of the Prior Art
Nowadays, among huge or small medical establishments, injection is done quite frequently for medical treatments. Most syringes are made of plastic material, and it is emphasized that safe syringes will be discarded after using, and will never be used repeatedly to prevent contagion. However, if the needle had been taken away from this kind of syringe, no one can assure whether the syringe has truly been discarded or not after using, so that lack of safety becomes a major hidden crisis.
Especially for those patients who need frequent injection, such as diabetics who need insulin injection or those narcotic drug addicts who need drug injection done by themselves, the conventional syringes they use can not be effectively forced to be discarded after injection. On the contrary, continuous requiring of using syringes in a long period of time may induce the idea of repeated use of a syringe or develop a habit to use them repeatedly. By all means, under advocacy of the anti-drug spirit, actively considering protecting the drug user""s sanitary behavior of injecting also has a specific value.
Moreover, after drawing out injection liquid, some syringes need to change its needle for one of a smaller size for the convenience of human body injection. But in changing the needle of a syringe, the metal needle is directly taken away from the front end of the syringe; during this short moment, the syringe without the metal needle fixed thereon might have the inside injection liquid contaminated, the injection liquid is subjected to back flowing out of the syringe. This is the second hidden crisis.
Therefore, it is the motive of the present invention to improve the above mentioned public used conventional syringes and eliminate its defects, and to provide a syringe which can prevent injection liquid from backflow and from contact with air or pollution sources and simultaneously can protect safety of patients by surely preventing recovery and reusing of the syringe.
The prime object of the present invention is to provide a structure of a syringe which can prevent backflow of injection liquid, and through the process of injection of such syringe, it can be guaranteed that there is no repeated use and can protect the body health of one who has an injection.
The secondary object of the present invention is to provide a backflow proof structure for a syringe of which the content will not contact with air or other pollution sources.
Another object of the present invention is to provide a structure which can prevent recovery and reusing of the syringe to thereby effectively guard the safety of all the national people.
To obtain the above-mentioned objects, the present invention is comprised of a central cylinder portion and a plurality of blocks which are all positioned in the protruding end of the syringe, the outer space of a tip on the top of the central cylinder portion is filled with a piece of crystallized syrup in order to separate a crown cap fitted over the top from the central cylinder portion, the central cylinder portion is placed in the protruding end, and a silicone cube is placed beneath the central cylinder portion as a pad, an irregular-shaped stopper closely contacts the bottom of the protruding end to thereby push the crown cap on top of the central cylinder portion out of the protruding end; when the syringe and the needle are connected with each other and the central cylinder portion is pressed down, the crown cap is pressed into the protruding end to form a passage; when the pressing force disappears, the silicone cube will bounce the central cylinder portion back to again let the flared portion on the bottom of the central cylinder portion block the outlet of the protruding end, this will effectively prevent backflow of the injection liquid or its contact with other pollution sources. All these are the features for the present invention.
The present invention will be apparent in its detailed structure and other features after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.